Skip Navigation Links
Centers for Disease Control and Prevention
CDC CDC Home Search Health Topics A-Z
Contact Help Travelers Health n i p Home NIP header
Health Care Professionals
First time visitor?
About NIP
Data and Statistics
International Efforts
Links to other web sites 
bullet Glossary/ Acronyms 

NIP sub-sites:
Flu Vaccine
Immunization Registries
Vaccines for Children Program
CASA (Clinic Assessment Program)
AFIX (Grantee Assessment)

NIP Site Search
For Immunization Information, call the
CDC-INFO Contact Center:
English and Spanish

Get Acrobat Reader
Get Adobe Reader
Home Health Care Professionals Home Partners Home Media Home Informacion en Espanol Health Care Professionals

Questions and Answers
NIP Answers Your Questions
Questions and Answers image

  Return to Q&A Main Page

General Questions

  • Under what circumstances would a person born before 1957 need MMR vaccine?

    Most persons born before 1957 are assumed to be immune to measles, mumps, and rubella because of the likelihood that they had the natural diseases. But adults who are at increased risk for exposure to and transmission of measles, mumps, and rubella should receive special consideration for vaccination. These persons include international travelers, persons attending colleges and other post-high school educational institutions, and persons who work at health-care facilities. In addition, all women of childbearing age should be considered susceptible to rubella unless they have received at least one dose of MMR or other live rubella virus vaccine on or after the first birthday, or have serologic evidence of immunity. Birth before 1957 is not acceptable evidence of immunity for women who could become pregnant. ACIP MMR Recommendations (see pages 16-17) (2/27/03)

  • How long should pregnancy be delayed after MMR vaccination?

    Women of child-bearing age should be counseled not to become pregnant during the 4 weeks after MMR vaccination. (This recommendation changed in 2001; prior to that it was 3 months.) MMWR Notice to Readers: ACIP Recommendation for Avoiding Pregnancy after Rubella-containing Vaccine (2/27/03)

  • Does MMR vaccine contain fetal or embryonic tissue? If so, what kind?

    The rubella vaccine virus is cultured in human cell-line cultures, and some of these cell lines originated from aborted fetal tissue, obtained from legal abortions in the 1960's. No new fetal tissue is needed to produce cell lines to make these vaccines, now or in the future. Fetal tissue is not used to produce vaccines; cell lines generated from a single fetal tissue source are used; vaccine manufacturers obtain human cell lines from FDA-certified cell banks. After processing, very little, if any, of that tissue remains in the vaccine. NIP Human Cell Cultures Webpage and Summary of Vaccine Contents (2/27/03)

  • Is it acceptable to give single-antigen measles for the second dose?

    Yes. ACIP recommends the combined MMR, but any measles-containing vaccine is acceptable. (2/27/03)

  • Sometimes we see patients who have received a single-antigen measles vaccine or a measles-rubella vaccine. Do they need one or two MMRs?

    As long as the measles-containing vaccine was a live vaccine administered on or after the first birthday, then only one MMR is necessary. ACIP MMR Recommendations (see page 11) (2/27/03)

  • If a child develops a fever and rash 10-14 days after MMR #1, does the child need a second dose of MMR at school entry?

    It would be difficult to definitely say that the rash is vaccine related. The child could have a rash totally unrelated to measles. We recommend that you administer the 2nd dose of MMR. (2/27/03)

  • Does measles disease exacerbate tuberculosis? Does this apply to MMR vaccine also?

    Measles disease can cause a person with a latent tuberculosis infection to develop active TB. Persons under treatment for tuberculosis have not experienced exacerbations of the disease when vaccinated with MMR. Although no studies have been reported concerning the effect of MMR vaccine on persons with untreated tuberculosis, a theoretical basis exists for concern that measles vaccine might exacerbate tuberculosis. Consequently, before administering MMR to persons with untreated active tuberculosis, initiating antituberculous therapy is advisable. Tuberculin testing is not a prerequisite for routine vaccination with MMR or other measles-containing vaccines. ACIP MMR Recommendations (see page 34) (2/27/03)

  • Our new employees must show proof of immunity to measles. What is considered acceptable evidence of immunity?

    In the ACIP recommendations for Immunization of Health Care Workers, measles immunity is defined as:

    a) physician-diagnosed measles;
    b) laboratory evidence of measles immunity (persons who
        have an “indeterminate” level of immunity upon testing should be
        considered nonimmune); or
    c) appropriate vaccination on or after the first birthday of two doses of
        live measles vaccine separated by at least 28 days.
    ACIP Immunization of Healthcare Workers Recommendations
    (see page 24) (2/27/03)

  • Should a dose of single-antigen measles vaccine given in Mexico be counted as valid?

    You can count a single-antigen measles dose from Mexico or any other country, as long as it was not given before the first birthday, as one of the two recommended doses of measles vaccine. The second dose should be an MMR given at least 28 days after the first dose and preferably at 4-6 years of age. ACIP MMR Recommendations (see page 11) (2/27/03)

  • Would you consider a person who has received two doses of MMR vaccine to be immune even if their serology for one or more of the antigens comes back negative?

    There is no ACIP recommendation for this situation. A negative serology would more likely be due to an insensitive test than true vaccine failure. However, there is the possibility, however unlikely, of a 2-dose vaccine failure. We would recommend that you give one more dose of MMR and stop testing. (2/27/03)

  • Our clinic serves Mexican immigrants. Should we offer MMR to the parents who bring their children to the clinic?

    This is really is a policy issue as well as an immunization issue. You need to discuss with your agency or your state immunization program whether you can provide immunizations to adults. If we're talking about the VFC program, only persons 18 years of age and younger are eligible. It is certainly advisable that whenever possible you assess the immunization needs of the entire family and give the vaccines indicated if your program allows. If not, then they should be referred to a health-care facility where they can be vaccinated. (2/27/03)

  • Why is there a two-dose recommendation for MMR but not for mumps and rubella?

    First, measles is more contagious than mumps or rubella. But also, the ACIP made the two-dose recommendation around the time of the measles resurgence of 1989-1991, when there were outbreaks involving huge numbers of people. Even though we know that people benefit from two doses of mumps and rubella as well, we've never had the resurgence of disease or the outbreaks that we've had with measles. There really hasn't been a reason, statistically speaking, to make that recommendation. However, two doses of MMR certainly doesn’t hurt. (2/27/03)

  • What is the source of gelatin in MMR vaccine and some other vaccines?

    The gelatin in the MMR vaccine is a highly hydrolyzed gelatin of porcine origin. Merck purchases it from a safe U.S. source (Dynagel Corporation) under the trade name “Sol-U-Pro”. (2/27/03)

  • In an area with immigrants and refugees that do not use birth control for religious reasons, is it acceptable to administer an MMR without a pregnancy test.

    ACIP does not recommend routine pregnancy testing prior to MMR vaccination. Women should be asked prior to vaccine administration if they are pregnant or plan to become pregnant within the next month. If the answer is no, they should be counseled regarding the theoretical risk to the fetus and advised to avoid pregnancy for one month (4 weeks) following vaccination. Then vaccinate them. (6/26/03)

  • If a dose of MMR is administered by the IM route, does it need to be repeated?

    No. Only Hepatitis B and rabies vaccines administered by nonstandard routes must be repeated. ACIP General Recommendations (see pages 13-14) (2/27/03)

  • Is it O.K. to give MMR in the thigh as long as it is given by the subcutaneous route?

    Yes, the subcutaneous tissue of either the thigh or the upper-outer triceps area of the arm is an acceptable subcutaneous injection site for MMR vaccine, (see page 12). (8/21/03)

  • What is the acceptable temperature range for storage of MMR vaccine?

    Before reconstitution, store the vial of lyophilized MMR vaccine at 2°-8°C (36°-46°F) or colder and protect from light at all times, since such exposure may inactivate the virus. MMR vaccine is a freeze dried (lyophilized) vaccine, therefore freezing will not affect potentcy. The diluent can be refrigerated or stored at room temperature, 15°-30°C (59°-86°F). It should not be frozen. It is recommended that the vaccine be used as soon as possible after reconstitution. Store reconstituted vaccine in the vaccine vial in a dark place at 2°-8°C (36°-46°F) and discard if not used within 8 hours, (8/21/03)



  • How soon can an MMR be given to a new mother who received RhoGAM after delivery?

    Postpartum administration of MMR or rubella vaccine to women who are susceptible to rubella should not be delayed because anti-Rho(D) immune globulin (human) or any other blood product was received during the last trimester of pregnancy or at delivery. Such rubella-susceptible women should be vaccinated immediately after delivery and tested at least 3 months later to ensure that they are immune to rubella and measles. ACIP MMR Recommendations (see page 35) (2/27/03)

  • If MMR is given 1 or 2 days before the first birthday, do you need to repeat the dose?

    Not if your state recognizes the 4-day grace period. Administering the first MMR dose a few days earlier than the 12-month minimum age is unlikely to have a substantially negative effect on the immune response to that dose. ACIP recommends that vaccine doses administered up to 4 days before the minimum interval or age be counted as valid.

    However, local or state requirements might mandate that doses of certain vaccines be administered on or after specific ages. For example, a school entry requirement might disallow a dose of MMR or varicella vaccine administered before the child’s first birthday. ACIP recommends that physicians and other health-care providers comply with local or state vaccination requirements when scheduling and administering vaccines. ACIP General Recommendations (see page 4) (2/27/03)

  • Should everyone receive 2 doses of measles vaccine or just high risk groups like college students?

    Two doses of MMR vaccine separated by at least 1 month (i.e., a minimum of 28 days) and administered on or after the first birthday are recommended for all children and adolescents through 18 years of age and for certain high-risk adults.

    A second dose of MMR is recommended for adults who: 1) were recently exposed to measles or are in an outbreak setting, 2) were previously vaccinated with killed measles vaccine, 3) were vaccinated with an unknown vaccine between 1963 and 1967, 4) are students in post-secondary educational institutions, 5) work in health-care facilities, or 6) plan to travel internationally. Childhood Immunization Schedule and Adult Immunization Schedule (2/27/03)

  • How long should I wait to give MMR after a dose of immune globulin?

    High doses of immune globulins can inhibit the immune response to measles and rubella vaccine for 3 or more months. The duration of this interference with the immune response depends on the dose of immune globulin administered. Blood (e.g., whole blood, packed red blood cells, and plasma) and other antibody-containing blood products (e.g., IG, specific immune globulins, and IGIV) can reduce the immune response to MMR or its component vaccines. Therefore, these vaccines should be administered to persons who have received an immune globulin preparation only after the recommended intervals have elapsed. Table 4 in the ACIP General Recommendations provides suggested intervals between the administration of antibody-containing products for different indications and measles-containing vaccine or varicella vaccine. (2/27/03)

  • Must MMR and varicella vaccines be given one month apart?

    No. They can be given on the same day. However, if they are not administered on the same day, they must be separated by at least 4 weeks. ACIP General Recommendations (see page 5) (2/27/03)

  • Can MMR and varicella vaccines be given on the same day but at different times, e.g., MMR at 9 a.m. and varicella at 4 p.m.?

    Yes, we define "simultaneous" in this context as the same clinic day. (2/27/03)

  • What do you do if MMR and varicella vaccines are given less than 28 days apart?

    The vaccine given second should not be counted as a valid dose and should be repeated. The repeat dose should be administered at least 4 weeks after the last, invalid, dose. ACIP General Recommendations
    (see page 5) (2/27/03)

  • Would you give hospital volunteers over 65 years of age measles vaccine if they have no evidence of immunization and a negative titer?

    Yes. Although birth before 1957 is generally considered acceptable evidence of measles immunity, serologic studies of hospital workers indicate that 5%–9% of those born before 1957 are not immune to measles. During 1985–1992, 27% of all measles cases among HCWs occurred in persons born before 1957 (CDC, unpublished data). ACIP strongly recommends that all HCWs be vaccinated against (or have documented immunity to) measles, mumps, and rubella. ACIP Immunization of Health-Care Workers Recommendations (see pages 10, 22) (2/27/03)

  • A 59-year-old secretary in our college health clinic has a negative titer for rubella. Should we vaccinate her?

    Yes. Persons born before 1957 generally are considered to be immune to rubella. However,findings of seroepidemiologic studies indicate that about 6% of HCWs (including persons born in 1957 or earlier) do not have detectable rubella antibody (CDC, unpublished data). ACIP strongly recommends that all HCWs be vaccinated against (or have documented immunity to) measles, mumps, and rubella. ACIP Immunization of Health-Care Workers Recommendations (see pages 11, 22) (2/27/03)

  • A 12-month-old child recently finished a course of Synagis. When can the MMR and varicella vaccines be administered?

    Any time. Synagis (palivizumab) is a monoclonal antibody containing only antibody to respiratory syncytial virus (RSV); hence, it will not interfere with immune response to live or inactivated vaccines. ACIP General Recommendations (see page 7) (2/27/03)

  • If an adult health-care worker has a negative measles titer, should she receive one or two doses of MMR and what is the interval between the two doses?

    It depends on the person's disease and vaccination history.

    If she has documentation of physician-diagnosed measles, this is adequate evidence of immunity and no doses of vaccine are recommended.

    If she has no documentation of physician-diagnosed measles but has documentation of one prior dose of live measles vaccine on or after the first birthday, give one dose of MMR.

    If she has no documentation of physician-diagnosed measles but documentation of two doses of live measles vaccine, this is considered adequate evidence of immunity. The negative titer is probably due to a serologic test that is not sensitive enough to detect antibodies, but since a 2-dose vaccine failure is theoretically possible we recommend you give one dose of MMR anyway.

    If she has no documentation of physician-diagnosed measles or documentation of any doses of live measles vaccine, give two doses of MMR separated by 28 days. ACIP Immunization of Health-Care Workers Recommendations (see page 24) (2/27/03)

  • A patient received a PPD and MMR #1 on the same day. The PPD reading indicated the need for a 2nd PPD, which should be given 2 weeks after the 1st PPD. What do you advise to avoid a false negative, since you recommend waiting 4-6 weeks to administer a PPD if it is preceded by an MMR?

    You should wait 4-6 weeks following the MMR vaccine to repeat the PPD to avoid the possibility of a false negative result. CDC's tuberculosis experts agree with the ACIP recommendation to delay the PPD in this situation. (2/27/03)

  • For a child (with all immunizations up to date) entering college this Fall, and living in the dorm, the meningococcal vaccine is recommended. It appears that the hepatitis A vaccine and revaccination with the MMR vaccine would also be useful - what are your thoughts?

    If the student is truly up-to-date with MMR (i.e., has had two doses), a third dose should not be needed. There is evidence that over 99% of people seroconvert for measles after two doses, with very high seroconversion rates for mumps and rubella as well.

    As for hepatitis A, there is no compelling reason to vaccinate students who do not live in high-incidence states or who are not otherwise at high risk (e.g., international travel, chronic liver disease). Strictly as a precaution, getting the vaccine can’t hurt, of course, but it isn’t routinely recommended. (6/26/03)

  • Regarding the two-dose administration of MMR to college students who do not have any documentation of immunity - what is the recommended time interval between the first and second dose?

    There should be a minimum of one month, which is defined as 4 weeks or 28 days, between doses of MMR vaccine. Table 1 in the ACIP General Recommendations on Immunization (page 3) provides a list of minimum intervals between vaccine doses of routinely recommended vaccines. (6/26/03)

  • My understanding is that healthcare workers, including those born before 1957 should have 2 MMR's or evidence of immunity to measles (rubeola), or 2 live measles vaccines and are exempt to rubella. Is this right? Please clarify.

    According to Table 2 of the ACIP Recommendations for Immunization of Health-care Workers (HCWs), vaccination with measles live-virus vaccine should be considered for all HCWs who lack proof of immunity, including those born before 1957. Table 2 provides the definitions of acceptable immunity. For mumps, adults born before 1957 can be considered immune. For rubella, adults born before 1957 can be considered immune, except for women who can become pregnant. If there is any doubt about immunity, then give an MMR as long as there are no medical contraindications. (6/26/03)

  • Would you please clarify who are the high-risk adults for whom two doses of MMR are recommended?

    Anyone born in 1957 or after who is a college student, an international traveler, or a healthcare worker should have two doses of MMR vaccine received after the first birthday and separated by at least 28 days. For healthcare workers, this means any healthcare worker who does not have evidence of immunity to measles and who shares air with a patient/client. Some agencies choose to do serologic testing for measles antibody. The two-dose recommendation for high-risk adults has been in effect since 1989. The risk for measles transmission from a healthcare worker to a patient is not as great in a long-term care setting because most geriatric patients are immune to measles, but it still exists. The greatest risk for measles transmission is in emergency rooms, urgent care centers, and physicians’ offices – wherever you take in sick people. This happens practically every time there is a measles importation into this country. You just don’t want any healthcare worker walking around susceptible to measles. (6/26/03)

  • If serologic antibody levels are below protective levels for measles in an adult, is it recommended that they receive a repeat MMR?

    It is unusual, but vaccine failure is possible (approximately 1/10,000) following two appropriately spaced doses of live-measles-containing vaccine. It is also possible that the laboratory test was not sensitive enough to detect the antibody. If this situation occurs, you can administer a 3rd MMR, document the dose and avoid further testing. If you must have documentation of the response after the 3rd dose, test 4 weeks after the 3rd dose when antibody response to the vaccine will be at peak. Vaccine failure to a 3rd dose is also possible, but even more unlikely (approximately 1/1,000,000). (6/26/03)



  • Can a person who is allergic to eggs receive MMR vaccine?

    Egg allergy is no longer considered a contraindication to MMR vaccine. In the past, egg protein was believed to be responsible for rare anaphylactic reactions following MMR vaccine. The concern now is that gelatin, which is used as a stabilizer in MMR, may be the culprit. Measles and mumps vaccine viruses are grown in chick embryo fibroblast tissue culture and don’t contain ovalbumin. Several studies have demonstrated the safety of MMR for persons with egg allergies. ACIP MMR Recommendations (see page 34) (2/27/03

  • Is a local reaction (e.g., hives) to topical Neosporin a ontraindication or precaution to MMR?

    Because MMR and its component vaccines contain trace amounts of neomycin (25 mcg), persons who have experienced anaphylactic reactions to topically or systemically administered neomycin should not receive these vaccines. However, neomycin allergy is most often manifested as a delayed or cell-mediated immune response (i.e., a contact dermatitis), rather than anaphylaxis. In persons who have such a sensitivity, the adverse reaction to the neomycin in the vaccine is an erythematous, pruritic nodule or papule appearing 48–96 hours after vaccination. A history of contact dermatitis to neomycin is not a contraindication to receiving MMR vaccine.
    ACIP MMR Recommendations (see pages 34-35) (2/27/03)

  • How common are adverse reactions after the second dose of MMR?

    We know that on average 95% (range, 90%-98%) of vaccinees respond to the first dose of MMR vaccine. Therefore, only 5% (range, 2%-10%) would be susceptible to adverse events associated with the 2nd MMR. We also know 5%-15% of those vaccinated experience one of the more common adverse events associated with MMR (e.g., fever or rash). Therefore, we would expect that only about 5% of the 5% who are still susceptible at the 2nd MMR vaccination would experience an adverse reaction. Pink Book Chapter: Measles (see pages 104 & 108) (2/27/03)

  • If a child develops varicella, or is exposed to varicella, before a dose of MMR is due, should the MMR be delayed? If a child develops varicella, or is exposed to varicella, just after receiving MMR, should the MMR be repeated?

    No to both questions. There is no evidence that active varicella disease interferes with the immune response to MMR. The only contraindication that could apply would also apply for any other vaccine: if the child is experiencing moderate to severe acute illness, wait until symptoms abate before vaccinating. (2/27/03)

  • Will steroids given within 2 weeks of receiving the MMR and varicella vaccines affect the immune response to these vaccines?

    The exact amount of systemically absorbed corticosteroids and the duration of administration needed to suppress the immune system of an otherwise immunocompetent person are not well-defined. A majority of experts agree that corticosteroid therapy usually is not a contraindication to administering live-virus vaccine when it is short-term (i.e., <2 weeks); a low to moderate dose; long-term, alternate-day treatment with short-acting preparations; maintenance physiologic doses (replacement therapy); or administered topically (skin or eyes) or by intra-articular, bursal, or tendon injection.

    Although of theoretical concern, no evidence of increased severity of reactions to live vaccines has been reported among persons receiving corticosteroid therapy by aerosol, and such therapy is not a reason to delay vaccination.

    The immunosuppressive effects of steroid treatment vary, but the majority of clinicians consider a dose equivalent to either at least 2 mg/kg of body weight or a total of 20 mg/day of prednisone or equivalent for children who weigh more than 10 kg, when administered for 2 weeks or more as sufficiently immunosuppressive to raise concern regarding the safety of vaccination with live-virus vaccines. Corticosteroids used in greater than physiologic doses also can reduce the immune response to vaccines. Vaccination providers should wait at least 1 month after discontinuation of therapy before administering a live-virus vaccine to patients who have received high systemically absorbed doses of corticosteroids for at least 2 weeks.
    ACIP General Recommendations (see page 23) (2/27/03)

  • If a child develops a rash following MMR or varicella vaccination but is otherwise well, can the child attend day care/school?

    For MMR, it is not a problem because there is no risk of transmission after vaccination. With varicella it is a little more complex. You have to use clinical judgment about what you think the rash looks like. Vaccine-associated varicella rashes tend to be mild, maculopapular lesions that are essentially noncommunicable. On the other hand, if the rash looks extensive, if it is vesicular, or you think the person might in fact have breakthrough varicella disease, the child could be infectious. It is possible to get infected with wild virus varicella after vaccination before the immune system has had a chance to mount an immune response to the vaccine. The bottom line is that if it looks like chickenpox, it should be treated like chickenpox. It would also depend on the policy of the day care/school. (2/27/03)

  • What is the frequency of seizures following MMR, if any?

    MMR vaccination, like other causes of fever, may trigger febrile seizures. The risk for such seizures is approximately 1 case per 3,000 doses of MMR vaccine administered. Studies have not established an association between MMR vaccination and residual seizure disorders. Although children with a personal or family history of seizures are at increased risk for idiopathic epilepsy, febrile seizures after vaccinations do not increase the probability that epilepsy or other neurologic disorders will subsequently develop in these children. Most convulsions that occur after measles vaccination are simple febrile seizures, which affect children who do not have other known risk factors for seizure disorders. ACIP MMR Recommendations (see page 29) (2/27/03)

  • Is it O.K. to administer MMR to a two-day postpartum woman who is not immune to rubella if her infant is in intensive care?

    Yes. Although a woman can excrete rubella vaccine virus in breast milk and transmit the virus to her infant, the infection remains asymptomatic and breast feeding is not a contraindication to vaccination. Otherwise, persons who receive MMR vaccine do not transmit measles, rubella, or umps vaccine viruses, ACIP MMR Recommendations (see page 33). (6/26/03)

  • Should immunosuppressed children receive MMR, Varicella, and PPD and should they receive them if they are in the household with immunosuppressed people?

    PPD is not a vaccine. It is a screening test for tuberculosis. It can be administered at the same time as MMR and varicella vaccines. Specific questions related to PPD administration should be directed to MMR and varicella vaccines should be administered to healthy persons who live in the household with someone who is immunosuppressed. You do not want to risk leaving the person susceptible and possibly bringing home measles, mumps, rubella, or varicella wild virus to an immunosuppressed person. MMR vaccine viruses are not transmitted through household contact. Transmission of varicella vaccine virus to a contact is not common. Most documented instances of vaccine virus transmission have occurred when the vaccinated person developed a rash. If the child develops a rash 7-21 days following vaccination, it is prudent to avoid prolonged close contact between the child and a usceptible person.

    Replication of vaccine viruses can be prolonged in persons who are immunosuppressed or immunodeficient. Evidence based on case reports has linked measles vaccine virus infection to subsequent death in six severly immunocompromised persons. For this reason, patients who are severely immunocompromised for any reason should not be given MMR vaccine, ACIP MMR Recommendations. ACIP now recommends varicella vaccination of children with humoral (but not cellular) immunodeficiencies. In addition, vaccination should be considered for children with HIV infection in CDC class N1 or A1 who have CD4+ T-lymphocyte percentages of 25% or higher. Additional details of these new recommendations can be found in the ACIP Varicella Recommendations. (8/21/03)

Top of page

National Immunization Program (NIP)
NIP Home | Contact Us | Help | Glossary | About | Accessibility

This page last modified on April 22, 2004


Department of Health and Human Services
Centers for Disease Control and Prevention
CDC Home
  |  CDC Search  |  CDC Health Topics A-Z